The invention relates to apparatus for monitoring the performance of open-end spinning machines, and more particularly to such types of monitoring apparatus having a digital readout.
In modern types of open-end spinning machines operating at automatically-controllable high speeds, efficient machine performance is often dependent on corrections made at several operating points of the machine. Such points may include the rotary spinning chamber, the combing-out cylinder which is associated with the spinning chamber for separating slivers into fibers to be spun into yarn by the spinning chamber, and the area of the machine which advances slivers into the working space of the combing cylinder. In addition, in order to ascertain total machine output and/or input-output efficiency, it is necessary to evaluate the rate of withdrawal of the yarn from the spinning chamber to the bobbins on which the yarn is cross-wound. Frequently, it is also desirable to monitor the operation of the distributing rollers, or other portions of the machine that impart twist into the yarn.
In order to monitor these various parameters, it is customary to associate, with the relevant portion of the machine, a portable or semi-portable tachometer of photoelectric probe, which in turn is coupled to circuitry peculiar to the particular measurement being taken. It is customary, particularly when measuring ratios of the measured quantities (e.g., to obtain the machine draft in number of twists per unit length or the ratio between the withdrawal speed of the yarn and the feeding speed of the input sliver) to employ special-purpose digital circuitry with the tachometer or probe.
A disadvantage of such known arrangements is the relatively long time delay necessary to adjust the special-purpose equipment involved for the successive measurements of separate parameters of the machine. This is particularly true in those cases where power is removed from the associated portion of the machine prior to measurement, whereby such time delay causes the speed of the monitored part to drop appreciably beyond the point where such monitoring is ideally effective for its intended purpose; such considerations are particularly significant during the measurement, e.g., of the braking efficiency of the spinning chamber and the combing cylinder.
Moreover, because of the special-purpose nature of the equipment necessary to monitor each of the various parameters of the machine in such prior arrangements, the measurements taken (even when converted into digital form) are not suitable for application to a central processor.